Sika postfix pros and cons

If you wish to set a fence post around your compound, you have to buy the right product. Most homeowners choose expanding foam such as Sika postfix.

This is a good expanding foam that can easily fill the cavity and create a strong seal within the surrounding soil. It is also lightweight, consistent, and sets in a few minutes. It does not require water or any special tools. The Sika postfix also requires less labor and works well on 4x 4 poles. Despite such advantages, Sika postfix does not work well for 6 x 6 poles. It is also not the best for soft grounds and has less compression strength. Here is more!

What is Sika postfix?

Though setting a fence post can seem difficult, getting the right product can make the experience easier. The Sika postfix is made up of polyurethane and resin. When mixed, Sika postfix creates an expanding foam that provides insulation for posts such as a mailbox, a fence, a lamppost, or a signage post.

what is Sika postfix

Sika postfix comes in a bag that has to be mixed before you start applying it. Once you mix and apply it, it will expand and harden. It can be used on PVC, steel, aluminum, and wooden supports. The manufacturer uses Sika foam technology in the creation of this expanding foam.

The merits of using Sika postfix

Even though the market has different types of expanding foams, the Sika postfix remains the most popular option due to its many benefits. It is a lightweight expanding foam that makes setting posts around a compound an easy task since it is simple to handle.

Since the application process is a breeze, you don’t need any experience to use this expanding foam. Once you purchase it, all you have to do is roll, mix, and then pour it into the desired hole. This foam sets in only three minutes and can therefore save you time. Since Sika postfix comes pre-proportioned, it can deliver an excellent performance.

Sika postfix is a versatile expanding foam that you can use to set posts made from different materials. It is designed to seal the hole and protect the base completely. Once you use this foam, you don’t have to worry about the post losing its stability quickly.

You can use it to set up a post even in the cold weather without requiring any additives. It is also a long-lasting product that can easily resist moisture infiltration. This foam is designed to expand; it goes an extra mile in terms of securing a post. Unlike using concrete, where you may require some water, you can use Sika postfix without water. You will not also need any special tools for you to apply this expanding foam as you set up a post.

Sika postfix pros

Does this expanding foam have any disadvantages?

Though Sika postfix may seem like the best-expanding foam for setting posts, you should understand its flaws. One of them is that it comes at a higher price compared to other types of expanding foams. You should, however, consider it since it can give you value for your cash. Some users also don’t like the lightweight of this expanding foam. They reveal that it is more like glue rather than an anchor.

Sika postfix also comes with a 33 fl. oz. bag. This quantity may not be sufficient to help you fill huge holes or even anchor 6×6 poles. You can only use it to fill gaps that are around 4×4 posts. Though the expanding foam works well on hard ground, it may not give you the best results on soft ground. It requires compacted ground for it to work as desired.

When you compare it with concrete, you will find out that Sika postfix has less compression strength. Unlike concrete which can be reused, Sika postfix is not reusable. If you still want to set a post using the Sika postfix, you should avoid exposing it to high heat conditions since this can accelerate the expanding reaction and make the bag burst before using it to fill the hole.

Here are the specifications of the Sika postfix

Cure time
3-5 minutes
Post size
4x4 poles
2.5 pounds
33 fl. oz
Call to action


Sika postfix is a good type of expanding foam that can help you secure posts in different positions well. It is easy to work with and offers a solid foundation for different posts. Since the cons are less than the pros, this is an expanding foam that is worth considering.


How long can the Sika postfix last after a signage post set up?

This is a durable expanding foam that can last for at least three years without breaking down.

Which is better, Sika postfix or concrete?

Sika postfix is better since it delivers better consistency up to the bottom layer of the soil. Though concrete can look solid on top, it may be brittle on the bottom part of a post.

William Smith

William Smith has been rendering his services to a botanical garden for the better part of his adult life and has recently moved to landscaping firms. His love for gardens has been nurtured since he was a kid, evident from the various garden centers and estates that have benefited from his services. Smith is a natural when it comes to gardening and when combined with his acquired degree in landscape design, you can expect a high-quality professional job, thanks to his experience and expertise. During his free time, Smith does gardening as a hobby and runs forums where he offers expert ideas on gardening.

Leave a Comment